Pre-development process for reducing fog in silver halide photographic materials

ABSTRACT

A method for reducing fog in photographic materials which are to be stored in formaldehyde containing atmospheres whereby a compound capable of reacting with and fixing said formaldehyde is incorporated into the silver halide emulsion of said photographic material. A light-sensitive silver halide photographic material which can be stored in a formaldehyde containing atmosphere without deterioration of photographic properties.

United States Patent Asano et a].

[ Mar. 28, 1972 PRE-DEVELOPMENT PROCESS FOR REDUCING FOG IN SILVER HALIDE A PHOTOGRAPHIC MATERIALS Inventors: Toshiaki Asano; Kazushige Uenaka, both of Kanagawa; Tomomasa Usami, Saitama, all of Japan Fuji Photo Film Co., Ltd., Kanagawa, Japan Filed: July 8, 1968 Appl. No.: 743,043

Assignee:

Foreign Application Priority Data July 8, 1967 Japan ..42/43902 u.s. c1... ..96/61, 96/109 Int. Cl. ..G03c 5/38, G03c 1/34 Field of Search ..96/l O9, 100, 66.4, 6 l 66.5

References Cited UNITED STATES PATENTS 7/1946 Kendall et al. ..;...96/l09 3,459,549 8/1969 McBride et al. ..96/Io9 3,141,771 7/1964 Bard et a]. ..96/66.4

FOREIGN PATENTS OR APPLlCATlONS 633,682 6/1962 Belgium OTHER PUBLICATIONS Mees, C. The Theory Of The Photographic Process, 1954, pp. 548- 551 Primary Examiner-Norman G. Torchin Assistant Examiner- Edward C. Kimlin Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [5 7] ABSTRACT 16 Claims, No Drawings PIKE-DEVELOPMENT PROCESS FOR REDUCING FOG IN SILVER IIALIDE PHOTOGRAPHIC MATERIALS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic material and more particularly to a silver halide photographic material containing an improved anti-fogging agent.

2. Description of the Prior Art It has been known that silver halide photographic materials on storage tend to lose their sensitivity and to form a fog due to various causes.

Although the extent of this fog has been considerably reduced, a certain degree of fog still is unaccountably formed, which reduces the quality of the photographic materials.

One of the causes has now been discovered as being the contaminants present in the containers in which the photographic materials are stored. Owing to the development of plywood technics, plywood is now used for making various types of furniture such as chest of drawers, desks, cabinets, and the like. The adhesives used in plywood furniture generally contain formalin as a hardener, such as in melamineformaldehyde resin'combinations or in phenol-formaldehyde resin combinations. Formalin is also used in furniture to provide insecticidal and antiseptic-effects.

It has now been found that when sensitive silver halide photographic materials are stored for a long period of time in such plywood furniture containing formalin adhesives, the quality of the photographic images obtained is seriously impaired by fog. Moreover, it has been found that in the case of color photographic materials, the image quality obtained from the material stored in such a condition is degraded even more seriously than for black and white photographic materials, since the three color gamma balance is lost.

Thus, an object of the present invention is to provide a means for reducing the fog produced in photographic materials, especially when the materials are stored in contact with formaldehyde gas. A further object is to provide a method for stabilizing photographic materials during storage under such conditions. A still further object is to provide a means for stabilizing the speed and contrast of the materials so stored. Other objects will appear from the following description of our invention.

SUMMARY OF THE INVENTION The above-mentioned objects of this invention can be attained by incorporating into the emulsion layer of a silver halide photographic material, at least one compound capable of reacting with and fixing formaldehyde gas.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The compounds capable of reacting with formaldehyde gas are described in, for example, 1. Frederick Wolker, Fonnaldehyde, Reinhold publishing corporation, New York, 1953. The examples thereof are (l) inorganic materials such as sodium sulfite, hydrazine hydrochloride, hydroxylamine hydrochloride, and the like; (2) aliphatic hydroxy compounds and mercaptans, such as alcohols, glycols, glycerines, mannitol, mercaptan, and the like; (3) ketones such as acetone, methylisobutyl ketone, cyclohexanone, acetylacetone, dimedone, and the like; (4) phenols such as phenol, 3,5- xylenol, mesitol, a-naphthol, 2,3-dihydroxynaphthalene, and the like; (5) carboxylic acids, acid anhydrides, acid chlorides, and esters, such as malonic acid, acetic anhydride, dimethylol malonic acid ester, and the like; (6) amines, amides, and nitrils, such as monomethylamine, dimethylamine, N,N'- ethylene urea, acetamide, N,N-diacetylethylene diamine, and the like; and (7) heterocyclic compounds such as furan, thiophene, pyrrole, pyrrolidine, and the like.

According to this invention, at least one of the aforesaid compounds is incorporated in a suitable concentration into a coating solution of a layer of the photographic material, such as, a silver halide emulsion layer, a subbing layer, an intermediate layer between two silver halide emulsion layers, a protective coating, and a filter layer. These coating solutions may be applied to a support such as glass plate, cellulose acetate film, polyethylene terephthalate film, baryta paper, and the like. The above compound may also be impregnated or diffused into the photographic layer of a photographic light-sensitive material.

Satisfactory results can be obtained when 0.0l g. to 10 g. of the compound per 1 sq. meter of the photographic material is incorporated or impregnated in the photographic layers. If the amount of the compound is less than 0.01 g., almost not satisfactory effects are obtained, whereas if the amount is larger than 10 g., the physical strength of the layers is often reduced. Especially in the case of color materials, the addition of a large amount of the compound may cause the formation of an unusual hue. However, if such faults may be tolerated, a larger amount than 10 g. may .be employed.

In admixing the aforesaid compound into a black and white silver halide photographic emulsion or a color photographic silver halide emulsion, the compounds of our invention may be added at any stage of the preparation of the said photographic materials. For example, the additive can be added that the solution of the said compounds is added to the coating solution just before coating.

The fog-inhibiting agents of the present invention can be used in the preparation of both black and white and color photographic materials. Thus, in the latter case, they may be used in photographic emulsions containing color couplers or color-forming compounds fast to diffusion, which are wellknown in the art, and capable of reacting with the aromatic amino developing agents to form color images, or in photographic emulsions which are developed in color developers containing color couplers, which are also well-known in the art.

Furthermore, the fog-inhibiting agents, which we have described may be used in various kinds of silver halide photographic materials. In addition to being useful in ordinary nonsensitive materials, they may also be used in orthochromatic, panchromatic and X-ray materials. Various silver halides may be used as the sensitive salt, such as silver bromide, silver iodide, silver chloride and mixtures of these. The dispersing agent may be gelatin or another colloid such as polyvinyl alcohol, albumin, polyacrylamide, etc. The silver halide photographic emulsions which may be used may be chemically sensitized by any of the accepted procedures. For example, the emulsions may be digested with naturally active gelatin, or sulfur compounds, such as sodium thiosulfate. The emulsions may also be chemically sensitized with gold salts such as potassium aurithiocyanate. Furthermore, the photographic materials according to our invention may also contain other agents known in the art, such as stabilizing agents, hardening agents, coating aids and the like.

It is considered that the aforesaid anti-fogging agents of our invention might selectively react with formalin gas, whereby the formation of fog by the presence of formaldehyde gas is prevented as well as the undesired overhardening of gelatin layers by the formaldehyde gas.

The present invention will be further illustrated by, but is not to be limited to, the following examples.

EXAMPLE 1 A high speed gelatino-silver iodo-bromide negative emulsion (silver iodide 5.0 mol percent), which has been chemically sensitized to its optimum with labile sulfur compounds and gold compounds, both well known in the art, was mixed with 65 ml. of a 0.1 methanolic solution of l,l'diethyl-2-2'- cyanine iodide as a spectral sensitizer per 1 mole of the silver halide, 20 ml. of a l percent aqueous solution of 4-hydroxy-6- methyl-1,3,3a, 7-tetrazaindene, as an anti-foggant, and 1.5 ml. of a 10 percent aqueous solution of chrome alum as a hardening agent. The coating composition thus prepared (1 kg.) was further mixed with 50 ml., 100 ml., 150 ml., and 200 ml.,

respectively, of a 5 percent aqueous solution of N,N-ethylene urea and then applied to polyethylene terephthalate film base and dried to produce a thin emulsion layer (2510.5 microns). The samples of these four light-sensitive films thus prepared were placed in a 3.0 liter closed vessel in which 300 ml. of a 35 percent aqueous glycerine solution containing 6 ml. of a 40 percent formalin was placed at the bottom of the said vessel, which thereafter was allowed to stand for 3 days at 35 C. The films thus incubated were developed in a D-76 type developer for lO'minutes at 20 C., and thereafter the fog density of the films was measuredThe results obtained are shown in thefollowing table.

N,N'-ethylene urea fog (control) 0.20 50 ml. 0.16 I00 ml. 0.") I50 ml. 0.08 "200 ml. 0.06

EXAMPLE 2 g A solution of 20 g..of potassium chloride, 7 g. of potassium bromide and 8 g. of gelatin in 230 ml. of distilled water was maintained at 55 C., whereupon a solution of 50 g. of silver nitrate in 920 ml. of distilled water was added over a period of 15 minutes while stirring. The temperature was maintained at 42 C. After the addition of 100 g. of gelatin, the emulsion was stirred for an additional 15 minutes, chilled with ice, shredded and washed with running water, until the conductivity of the emulsion was 1,500 microhms/cm. The emulsion was thereafter remelted.

To the emulsion there were then added 2.4 g. of active gelatin and 80 g. of inert gelatin, and the emulsion was afterripened for 100 minutes at 55 C. To 1 kg. of the emulsion thus obtained were added 100 ml. of a 0.1 percentmethanolic solution of anhydro-S ,5 '-tetrachloro-l l '-diethyl-3,3'- dibenzimidazolocarbocyanine hydroxide as a spectral sensitizer, and 200 ml. of a percent alkaline solution of l-phenyl-3-(3 (2-carboxymethyl-3-eicosenamido)benzimido)-5- pyrazolone as a magenta dye forming coupler.

The coating composition thus prepared 1 kg.) was further mixed with the amounts indicated in the following table of a 5 percent aqueous solution of N,N-ethyle'ne urea, and then coated on cellulose triacetate film base which had previously been given a subcoating, and dried to produce a thin emulsion layer of about 5 microns thickness. The resulting coatings were incubated as in Example 1, and developed for 12 minutes at 20 C. in a developer of the following composition;

Hydroxylamine hydrochloride l.4 g. Sodium sulfite (anhydrous) 2.0 g. Potassium carbonate 25.0 g. Potassium bromide 2.0 g. Diethyl-p-phenylenediamine sulfate 3.2 g. Water to make l.0 liter N.N'-eihylene urea fog 0 (control) 0.92 50 ml. 0.65 100ml. 0.44 150 ml. 0.38 200 ml. 0.33

EXAMPLE 3 A high speed gelatino-silver iodo-bromide negative emulsion (silver iodide 5.0 mol percent), which has been chemically sensitized to its optimum with labile sulfur compounds and gold compounds, both well known in the art, was mixed with a 0.05 percent methanolic solution of 3,3 '-dimethyl-9- phenyl-4,5; 4,5-dibenzothiocarbocyanine chloride as a spectral sensitizer, 20 ml. of a 1 percent aqueous solution of 4- hydroxy-o-methyl-l ,3,3a,7-tetrazaindene as an anti-foggant, and 1.5 ml. of a 10 percent aqueous solution ofchrome alum as a hardening agent per l mole of the silver halide, ml. The coating composition thus prepared (1 kg.) was further mixed with 50 ml., 100 ml., ml., and 200 ml., respectively, of a 5 percent aqueous solution of 2,3-dihydroxy-naphthalene, and then applied topolyethyleneterephthalate film base which had previously been given a subcoating, and dried to produce a thin emulsion layer (3 10.5 microns). The resulting coatings were incubated as in Example 1, and developed in a D-76 type developer for 10 minutes at 20 C. The fog densities of the resulting strips were measured and the-results obtained shown in the following table.

2,3-Dihydroxynaphthalene Fog 0 (control) I 0.32 50 ml. 0.20 .l00 ml. 0.10 l50 ml. 0.08 200 ml. 0.06

EXAMPLE 4 ml. of a 10 percent aqueous solution of chrome alum as a hardening agent per l'mole of silver halide. The coating composition thus prepared (1 kg.) was further mixed with 50 ml., 100 ml., 150 ml., and 200 ml., respectively, of a 5 percent methanolic solution of dimedone and then coated on cellulose triacetate film base which had been previously given a subcoating, and dried to produce a thin emulsion layer (4.0 1': 0.5 microns).

The resulting coatings were incubated as in Example I, and developed in a D'76 type developer, for 5 minutes at 22 C. The fog densities of the films were then measured. The results obtained are shown in the following table:

Dimedone Fog 0 (control) 0.22

I00 ml. 0.15

What is claimed is:

1. An undeveloped light-sensitive silver halide photographic material comprising a support bearing thereon photographic layers containing in at least one layer thereof a photographically compatible compound capable of reacting with and fixing formaldehyde gas, whereby upon storing said undeveloped material the formation of fog due to the presence of formaldehyde under the storage conditions is reduced.

2. The light-sensitive silver halide photographic material of claim 1, wherein said compound is selected from a group consisting of N,N'-ethylene urea, 2,3-dihydroxy naphthalene, and l l -dimethyl-3 ,S-diketocyclohexane.

3. The light-sensitive photographic material of claim 1 wherein at least one of said photographic layers is a gelatinosilver halide emulsion layer.

4. The light-sensitive silver halide photographic material of claim 3 wherein said gelatino silver halide emulsion layer contains a color forming compound which is fast to diffusion and which is capable of reacting with the product of aromatic amino developing agents to form a colored image.

5. The light-sensitive silver halide photographic material of claim 1 whereinthe amount of said compound is from 0.01 g. to g. per 1 square meter of said material.

6. The material of claim 1 wherein said photographic material is also unexposed.

7. The material of claim 1 wherein said compound is selected from the group consisting of sodium sulfite, hydrazine hydrochloride, hydroxylamine hydrochloride, aliphatic hydroxy compounds, mercaptans, ketones, phenols, carboxylic acids, acid anhydrides, acid chlorides, esters, amines, amides, nitrils, furan, thisphene, pyrrole and pyrrolidine.

8. The material of claim 7 wherein said compound is an inorganic material selected from the group consisting of sodium sulfite, hydrazine hydrochloride, and hydroxyl amine hydrochloride.

9. The material of claim 7 wherein said compound is an aliphatic hydroxy compound selected from the group consisting of alcohols, glycols, gylcerines and mannitol.

10. The material of claim 7 wherein said compound is a mercaptan.

11. The material of claim 7 wherein said compound is a ketone selected from the group consisting of acetone, methylisobutyl ketone, cyclohexanone, acetylacetone and l ,1-dimethyl-3 ,S-diketocyclohexane.

12. The material of claim 8 wherein said compound is a phenol selected from the group consisting of phenol, 3,5- xylenol, mesitol, a-naphthol and unbridged 2,3-dihydroxynaphthalene.

13. The material of claim 8 wherein said compound is selected from the group consisting of malonic acid acetic anhydride and dimethylol malonic acid ester.

14. The material of claim 8 wherein said compound is selected from the group consisting of monomethylamine, dimethylamine, N,N'-ethylene urea, acetamide and N,N'- diacetylethylene diamine.

15. The material of claim 8 wherein said compound is selected from the group consisting of furan, thiophene, pyrrole and pyrrolidine.

16. A process for reducing fog in an undeveloped light-sensitive silver halide photographic material comprising a support bearing thereon photographic layers which comprises:

a. incorporating in at least one of said photographic layers of said silver halide photographic material prior to development a photographically compatible compound which reacts with and fixing with formaldehyde gas; and

b. storing said light-sensitive silver halide photographic material containing said at least one compound in an atniosphere containing formaldehyde, whereby the formation of fog due to the presence of formaldehyde is reduced by reaction and fixing with said compound. 

2. The light-sensitive silver halide photographic material of claim 1, wherein said compound is selected from a group consisting of N,N''-ethylene urea 2,3-dihydroxy naphthalene, and 1,1-dimethyl-3,5-diketocyclohexane.
 3. The light-sensitive photographic material of claim 1 wherein at least one of said photographic layers is a gelatino-silver halide emulsion layer.
 4. The light-sensitive silver halide photographic material of claim 3 wherein said gelatino silver halide emulsion layer contains a color forming compound which is fast to diffusion and which is capable of reacting with the product of aromatic amino developing agents to form a colored image.
 5. The light-sensitive silver halide photographic material of claim 1 wherein the amount of said compound is from 0.01 g. to 10 g. per 1 square meter of said material.
 6. The material of claim 1 wherein said photographic material is also unexposed.
 7. The material of claim 1 wherein said compound is selected from the group consisting of sodium sulfite, hydrazine hydrochloride, hydroxylamine hydrochloride, aliphatic hydroxy compounds, mercaptans, ketones, phenols, carboxylic acids, acid anhydrides, acid chlorides, esters, amines, amides, nitrils, furan, thisphene, pyrrole and pyrrolidine.
 8. The material of claim 7 wherein said compound is an inorganic material selected from the group consisting of sodium sulfite, hydrazine hydrochloride, and hydroxyl amine hydrochloride.
 9. The material of claim 7 wherein said compound is an aliphatic hydroxy compound selected from the group consisting of alcohols, glycols, gylcerines and mannitol.
 10. The material of claim 7 wherein said compound is a mercaptan.
 11. The material of claim 7 wherein said compound is a ketone selected from the group consisting of acetone, methylisobutyl ketone, cyclohexanone, acetylacetone and 1,1-dimethyl-3,5-diketocyclohexane.
 12. The material of claim 8 wherein said compound is a phenol selected from the group consisting of phenol, 3,5-xylenol, mesitol, Alpha -naphthol and unbridged 2,3-dihydroxynaphthalene.
 13. The material of claim 8 wherein said compound is selected from the group consisting of malonic acid acetic anhydride and dimethylol malonic acid ester.
 14. The material of claim 8 wherein said compound is selected from the group consisting of monomethylamine, dimethylamine, N, N''-ethylene urea, acetamide and N,N''-diacetylethylene diamine.
 15. The material of claim 8 wherein said compound is selected from the group consisting of furan, thiophene, pyrrole and pyrrolidine.
 16. A process for reducing fog in an undeveloped light-sensitive silver halide photographic material comprising a support bearing thereon photographic layers which comprises: a. incorporating in at least one of said photographic layers of said silver halide photographic material prior to development a photographically compatible compound which reacts with and fixing with formaldehyde gas; and b. storing said light-sensitive silver halide photographic material containing said at least one compound in an atmosphere containing formaldehyde, whereby the formation of fog due to the presence of formaldehyde is reduced by reaction and fixing with said compound. 